In China, there are two patent documents that relate closely to the method and system for automatically identifying information of a train prescribed by the present invention. One is titled “EQUIPMENT FOR DISTINGUISHING PASSENGER TRAIN FROM GOODS TRAIN BY BETWEEN-CARRIAGE GAP COUNTING METHOD” (CN1164449C), which was granted the patent right on Sep. 1, 2004 under the application number of 02117867.4. The equipment for distinguishing passenger train from goods train by between-carriage gap counting method is characterized in that it uses two wheel passive magnetic sensors to determine the total length of the carriages to be analyzed, and dynamically detect the number of gaps between the carriages by using photoelectric sensors installed between them. Since the carriages of a passenger train are connected to each other and detecting light can not pass through them, the only pulse that can be produced originates from the gap between the locomotive and the first carriage. In contrast, there is a gap of approximately half a meter between two goods carriages. Therefore, within the total length of the carriages determined by the above two magnetic sensors, the train can be identified to be a goods train when number of the gap pulses is counted to be greater than or equal to a predefined threshold of the number of gaps, otherwise it is determined to be a passenger train. When the counting starts and ends is determined by a wheel arriving signal from the above two magnetic sensors.
The second patent document is titled “METHOD AND SYSTEM FOR DISTINGUISHING PASSENGER TRAIN FROM GOODS TRAIN BY BETWEEN-WHEEL SPACING METHOD” (CN1151045C), which was granted the patent right on May 26, 2004 under the application number of 02117863.1. The method and system for distinguishing passenger train from goods train by between-wheel spacing method comprises 4 magnetic sensors, and is based on the reality that the spacing between two groups of wheels of the passenger train is greater than that of goods train. Said 4 magnetic sensors are mounted at either rail on the side of the detection surface along the incoming direction of the drain, and comprises one pair of magnetic sensors for identifying the spacing between two wheels of which the distance between the centers is equal to that between the centers of a group of wheels, one magnetic sensor for shielding locomotive and generating a signal for beginning recognition, and another magnetic sensor for sensing arrival of locomotive, ending the recognition and reading the result. If the two magnetic sensors for identifying the spacing between two wheels respectively receive a wheel arrival pulse at the same instant, it can be determined that the train is a goods train, otherwise a passenger train.
Sometimes, in order to transport goods of large length, such as timber, two flat carriages need to be connected for use. In such a situation, the first method in the prior art for judging the passenger train or goods train will not be reliable. And besides, the photoelectric sensor is susceptible to influences from external environments such as sun light, rain, snow, and insects, and is prone to misoperation. As for the second method, it can be understood as following: if the wheelbase of a bogie is greater than a certain value, a passenger train is determined, and a goods train if smaller than a certain value. This method has a higher requirement for the positioning of the sensors, and is quite limited in train types. Besides, neither method can accurately provide the speed of a passing train, segmentation information, locating information or the like.